What Does A Hard Lump On Penis Indicate?

I noticed a small hard lump on my penis three days ago. I thought it might be a pimple only it was very hard . I tried to squeeze it but nothing happened! The size grew very quickly overnight and now it seems very infected as it is really hard and swollen into one big lump ! I started using polysporin today but I don t know what it is or if this will help. Can you please help me?